Damper control



April 10, 1934- H. GEROW 1,954,125

DAMPER CONTROL Filed Oct. 12, 1932 UNITED STATES PATENT OFFICE DAMPER CONTROL Leonard H. Gerow, Toledo, Ohio Application October 12,

2 Claims.

The invention relates to dampers for controlling the draft escaping through fines of furnaces, and the like, but more particularly to devices for automatically actuating or rocking the damper 5 to effect the desired opening for the flow of gases, and the products of combustion, in accordance with the demands of service.

An object is to produce a simple and efficient control for a damper operable automatically for gradually closing the passage when the draft exceeds a predetermined minimum, the movement of the damper being effected by difierential gaseous pressures within a casing which causes movement of a member operatively connected to the damper.

An object is to produce a damper control which is capable of maintaining a uniform draft on the furnace of any predetermined intensity within the limits of the draft of the smoke passage.

Another object is to produce an adjustable regulating device for a damper control of the above type, which can be readily and conveniently operated, for controlling the closing of the damper in accordance with the desired draft conditions.

The invention is shown by way of illustration, but not of limitation, in the accompanying drawing, in which: V

Figure 1 is a side elevation of the damper controlling device mounted at one side of a i furnace flue;

comprises a pipe 10, which may be a flue, smoke stack, or other conduit through which hot gases or other products of combustion pass from a fire box to the outside. Mounted therein is a damper plate 11, having its end portions bent in opposite directions substantially as shown, as indicated at 12 in Figure 1, so that when the damper is in fully closed position a sufficient opening is provided for the passage of some gases to prevent complete choking off of the draft for obviating any possible danger.

As shown, the damper plate 11 is mounted on a shaft 13, one end of which extends outside of the pipe 10 into a housing 14. The housing 14 is generally of triangular shape, and mounted therein for swinging movements is a vane or dia- 1932, Serial No. 637,477

phragm 15, which has a relatively close fit with the side walls of the housing, the arrangement being such that the vane is free to swing inside of the housing, and, for this purpose the outer wall 16 thereof is arcuately shaped. While the housing 14 is shown mounted in close juxtaposition to the flue pipe 10, it may be arranged at a distance from the pipe, if desired.

The vane 15 is normally disposed in upright position, as shown in Figure 3, and counter-balancing the weight of the vane 15 is an arm 17, which is connected to the opposite end portion of the shaft 13, and has an adjustable weight 18 on the lower end portion thereof. The bottom wall of the housing 14 communicates by a conduit 19 with the inside of the pipe 10 in rear of the damper 11. As shown, the rear wall 20 of the housing 14 provides a door, which is hingedly connected at 21 thereto, and friction.- ally overlaps the adjacent side walls. An opening 22 is provided in the upper portion of the door 20 to permit atmospheric pressure to be exerted on outer side of vane so that due to the rarefication in the pipe 10, the vane will be rocked to the left of Figure 3. The amount of'this movement is dependent upon the degree of rarefication in the pipe 10, which varies with the movement of the damper.

It is manifest that the more the vane 15 is moved to the left of Figure 3, the more nearly closed will be the damper 11. In this manner the more draft developed in the pipe 10, the more the damper 11 will be closed to conserve heat as much as possible for preventing loss of the greater portion of heated gases to the'outside. Furthermore, in accordance with the oper-' ation of the above device, a uniform draft is maintained at all times so that only the desired volume of air is drawn into the furnace which the latter can efiiciently handle. From the above description it is apparent that this action takes place automatically, and when the degree or rarefication has been reduced the damper will accordingly be opened wider to afford a freer passage through the pipe 10.

Means are provided for manually controlling the automatic movement of the damper 11, and for this purpose an arm 25 is screwed through the arm 17 and the shaft 13. The arm 25 is connected by a link 26 to a follower 27 disposed within a tubular casing 28. Disposed in the casing 28 are coil springs 29 and 30, and disposed between these springs is a disc 31 mounted on a. stem 32 extending longitudinally of the casing and terminating outside thereof. An adjustable block 33 on the stem 32 enables the compression of the spring 30 to be regulated. The casing 28 is mounted in a sleeve bracket 34, which in this instance is secured to the casing 14. Connected to the outer end of the stem 32 is a chain 35, which may lead to any suitable remote control.

The casing 28 is moved within the sleeve bracket 34 eitherupwardly or downwardly to regulate the initial force of the spring 29 for increasing or diminishing the resistance imposed upon the movement of the vane 15. Thereupon, the bracket is secured to the casing for holding the latter in position. This adjustment may be supplemented by an adjustment of the arm 25 relative to the arm 24. Thus, when it is desired to prevent closing movement of the damper 11 until a greater suction is created within the pipe 10, the casing 28 is adjusted to the proper position so that the tension of the spring 29 is increased. In addition, the collar 33 may be adjusted with respect to the disc or head 31 to vary the compression of the spring 30.

It is apparent that by pulling upwardly on the chain 35 the disc 31 through the stem 32 is moved upwardly compressing the spring 30, but alloving the sprin 29 to expand, and thereby weakening the resistance to the movement of the arm 26 so as to enable the damper 11 to be actuated by the vane 15 more readily. The more the disc 31 is moved upwardly in the casing 28, the less will be the resistance to the closing movement of the damper 11 through the vane 15. Conversely, the more the spring 29 is compressed, the more pressure will be required to move the vane 15 to cause the damper 11 to move toward closed position, and, consequently, a greater suction will be necessary in the pipe 10 to impart closing movement to the damper 11. By means of this regulating device the operation of the damper control device may be readily and conveniently controlled in accordance with the demands of service. The regulating device may be mounted on the casing of the damper control device, or elsewhere, and may be actuated from a remote point without difiiculty.

From the above description, it will be understood that when the fire in the fire box is low, as much draft as possible is desired, and, for this purpose, the damper 11 is fully open. As the intensity of the fire increases, a greater draft through the flue pipe 10 is created, and the rarefication of the air in advance of the vane enables the atmospheric pressure to swing it in a counter clockwise direction (Fig. 3). This operates to move the damper 11 toward closed position, and the greater the draft caused by a hotter or more intense fire, the more the damper is automatically moved toward closed position. The withdrawal or loss of the hot air in the furnace will thus be largely prevented. By the spring regulating device above described, it is manifest that the action of the vane may be controlled in order to check the fire or stimulate the draft according to the degree desired. While the damper control is particularly adapted for use in connection with coal-burning furnaces, it is not intended that the invention be limited solely thereto.

It is to be understood that the invention is not limited to the particular arrangement shown, since numerous changes in details of construction, arrangement and operation may be effected without departing from the spirit of the invention, especially as defined in the appended claims.

What I claim is:

1. A damper control for a furnace having a fine, shaft means extending transversely thereof, a damper in said fiue directly connected intermediately to said shaft means, said control comprising a substantially triangular shaped casing arranged in close juxtaposition to said flue, said casing being closed except for an opening to the outside at one end and a conduit at the opposite end leading to said flue in rear of said damper,

a vane disposed normally at substantially right angles to said flue and having a relatively close fit in all positions within said casing and disposed between said opening and conduit, said shaft means extending directly from said flue into said of said vane and said shaft means whereby said damper and vane move conjointly, said vane being disposed at substantially right angles to said damper in all positions of movement, and a weighted arm on said shaft means for counterbalancing said vane and tending to hold same in normal position.

2. A. damper control for a furnace having a flue, shaft means extending transversely thereof, a damper in said flue directly connected intermediately to said shaft means, said control comprising a substantially triangular shaped casing arranged in close juxtaposition to said flue, a cover closing one end of said casing having a relatively small opening therein adjacent the upper end thereof, a conduit leading from the opposite end of said casing to said flue in rear of said damper, a vane disposed normally at substantially right angles to said fine and having a relatively close fit in all positions within said casing and disposed between said opening and conduit, said shaft means extending directly from said flue into said casing, a connection between one end of said vane and said shaft means whereby said damper and vane move conjointly, said vane being disposed at substantially right angles to said damper in all positions of movement, and a weighted arm on said shaft means for counterbalancing said vane and tending to hold same in normal position.

LEONARD H. GEROW.

casing, a connection between one end 

